• Journal of Korea Soil Environment Society
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• v.5 no.1
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• pp.45-54
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• 2000

Several chemical washing procedures were applied to Zn and Cd contaminated soil. Batch and column tests were performed to determine the metal extraction efficiency as a function of pH and concentration. Washing efficiencies by water and NaOH are very low but those by HCI, EDTA and Oxalic acid are high. The most efficient washing occurs in case of using HCI because heavy metal is ionized easily at the condition of low pH. EDTA and Oxalic acid are also effective to extract Zn and Cd because they have a high complexation affinity for heavy metals forming active surface complexes. More Zn is released than Cd is and release trend is increased as pH is decreased and concentration of washing solution is increased. When heavy metal contaminated soil is remediated, HCI and EDTA are more effective to remove Zn than others are. Meanwhile HCI and Oxalic acid are more effective to remove Cd than others are.

• Journal of the Korean Wood Science and Technology
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• v.49 no.1
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• pp.14-22
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• 2021

The objective of this study was to investigate the effect of alkali-washing with different sodium hydroxide concentrations on the chemical compositions of steam-treated Betung bamboo strand. Strands were subjected to steam treatment at 126 ℃ for 1 h under 0.14 MPa pressure and followed by washing with 1-5% sodium hydroxide solution for 30 sec. The alteration of structural and non-structural chemical components content of bamboo strands was evaluated. Steam and washing treatments with various concentrations of sodium hydroxide solution considerably reduced the extractive content of bamboo strands, and the cell wall chemical components of the strand in the small degree. FTIR analysis showed noticeable changes in peaks related to hemicellulose and lignin. The relative crystallinity increased significantly after steam and washing treatment with sodium hydroxide up to 3% concentration. SEM Images showed smooth and clean strands surface after washing with 3% sodium hydroxide.

• Journal of Soil and Groundwater Environment
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• v.27 no.5
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• pp.10-17
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• 2022

Inorganic acids such as HCl, HNO₃, and H₂SO₄ have been commonly applied to soil washing of heavy metals-contaminated soil due to their cost-effectiveness. However, implementing the 'Chemical Substance Control Act' requires off-site risk assessment of the chemicals used in the soil washing. Therefore, in this study, organic acids or Fe(III)-based washing agents were evaluated to replace commonly used inorganic acids. Ferric removed heavy metals via H⁺ generated by hydrolysis, which is similar to the HCl used in the control group. Oxalic acid and citric acid were effective to remove Cu, Zn, and Cd from soil. Organic acids could not remove Pb because they could form Pb-organic acid complexes with low solubility. Furthermore, Pb could be adsorbed onto the iron-organic acid complex on the soil surface. Ferric could remove exchangeable-carbonate, Fe-Mn hydroxide, and organic matter and sulfides bound heavy metals (F1, F2, and F3). Organic acids could remove the exchangeable-carbonate and Fe-Mn hydroxide bound metals (F1&F2). Therefore, this research shows that the fractionation of heavy metals in the soil and the properties of washing agents should be considered in the selection of agents in the process design.

• Analytical Science and Technology
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• v.30 no.5
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• pp.270-278
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• 2017

The absorption of blood onto the surfaces of white cotton, polyester, rayon, and nylon fabrics was studied. Different categories of fabrics (woven and knitted) with diverse thickness, were manually folded twice to obtain four fabric layers, and $100{\mu}L$ of human blood was dropped onto the surface of the fabrics. The amount of blood that penetrated the fabric layer and the shape of bloodstain observed on the fabrics were influenced by the chemistry, thickness, and texture of the fabric. The blood bearing fabrics were left to dry for 3 days, washed by hand using tap water, and Lumiscene was then sprayed onto the fabrics to enhance the latent bloodstain for comparison of the shape of the bloodstain before and after washing by hand. The features of the bloodstain after washing varied greatly with the recipient fabrics. Additionally, stronger luminescence was observed at the surface where the blood was deposited compared to the background. However, it was confirmed that physical contact during the washing can deform the original shape of the bloodstain. The effect of the drying time on the bloodstain after hand washing was also studied. $100{\mu}L$ of blood was dropped on the surfaces of the fabrics and dried for 0, 1, 12, 24, 72 h, and 7 days, then washed by hand, before the bloodstain was enhanced with Lumiscene. The results of this experiment indicated that the increased drying time induces stronger chemiluminescence of Lumiscene. However, after drying of the bloodstain for 7 days, the luminescence of the bloodstain was decreased at the blood deposited site and increased around the blood deposited site.

• Journal of the Korea Institute of Building Construction
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• v.15 no.2
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• pp.169-175
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• 2015

Recently, a stone is preferred as a cladding materials because of its outstanding durability and luxurious character. However, because of running out of natural resources and restriction of production, it is expected that difficulty of stable supply, and thus alternative cladding materials for concrete wall is needed. Therefore, in this research, as an alternative cladding materials, exposed-aggregate concrete is studied using saccharin based retarder. For evaluating factors, changing water-to-cement ratio, dosages of saccharin-based retarder, and timing of water jet washing were tested on the surface properties of exposed-aggregate concrete. As a result, the most favorable surface performance was obtained at 0.75 day after the placing in 25% of water-to-cement ratio, and at one day after the placing in 35 and 55% of water-to-cement ratio, 1.5 day after the placing in 65% of water-to-cement ratio with $24m{\ell}/m^2$ of retarder application.

• Journal of Soil and Groundwater Environment
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• v.11 no.6
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• pp.61-68
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• 2006

Soil washing techniques coupled with high pressure air jet were applied for diesel-contaminated soils sampled by an underground oil reservoir of which the initial total petroleum hydrocarbon (TPH) ($2,828{\pm}206\;mg/kg$) exceeded 5 times of current standard level (500 mg/kg) regulated by the Soil-Environment Conservation Law. Through several tests, we found that the position of impeller has a critical impact for washing efficiencies. The highest washing efficiency was obtained at an oblique angle (30 degree) for the impeller and optimized mixing speed (300 rpm) that could have high shearing forces. Considered economical and feasible aspects, the optimum mixing time was 10 min. Rate constants of TPH removal derived from the first-order equation were not linearly increased as mixing speed increased, indicating that mechanical mixing has some limits to enhance the washing efficiencies. Application of high-pressure air jet in washing process increased the washing efficiency. This increase might be caused by the fact that the surface of micro-air bubbles strongly attached hydrophobic matters of soil particles. As the pressure of air jet increased, the separation efficiencies of TPH-contaminated soil particles increased. In the combined process of high-pressure air jet and mixing by impeller, the optimum mixing speed and air flow-rate were determined to be 60 rpm and $2\;kg/cm^2$, respectively. Consequently, the washing technique coupled with high-pressure air jet could be considered as a feasible application for remediating petroleum-contaminated soils.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.18 no.1_2
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• pp.39-44
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• 2012

This study investigated the changes in the quality of minimally processed sliced Deodeok (Codonopsis lanceolata) during storage at $7^{\circ}C$ in relation to vacuum packing using PE film after the various surface washing treatments. The surface washing treatments resulted in approximately 1~2 log CFU/g reduction of microbial load in the early storage day. After 20 days, the weight loss rate, deterioration rate, hardness, color, total microorganism levels and the coliform count of deodeok washed by ultrasonic wave water was deteriorated rapidly like the control. When measured by the fresh-cut deodeok surface using the video microscope system, washing with chlorine water and electrolyzed water didn't seem to make perceivable quality deterioration during the 10 days at $7^{\circ}C$. The hardness and color maintenance of the product vacuum packaged using PE film after washing with electrolyzed water, was better than that of other treatments.

• Carbon letters
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• v.3 no.4
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• pp.198-204
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• 2002

In this paper, impregnated activated carbon fiber (IACF) was manufactured to pitch-based activated carbon fibers (ACF) with potassium hydroxide (KOH) by using wet impregnation method to raise nitrogen oxides ($NO_x$) adsorptivity. The properties of IACF were observed using EPMA, TGA and DSC and $NO_x$ adsorptivity was observed at high and low temperature. Before and after adsorption was analyzed using ToF-SIMS for examine surface characterization of adsorbed $NO_x$. The results showed that the better adsorptivity appeared for increasing KOH ratio. So, $NO_x$ adsorptivity showed result that is proportional between KOH and the adsorbed amount. On the other hand, adsorbent that manufactured without washing was better $NO_x$ adsorptivity than adsorbent that manufactured with washing. The behavior of adsorption show that crossing time of NO and $NO_2$ delayed for a rising adsorptivity. And NO ratio increased but $NO_2$ ratio decreased according as KOH ratio increases. $NO_x$ was confirmed through surface analysis that remain in $NO_2^-$ and $NO_3^-$ form on IACF surface.

• Fashion & Textile Research Journal
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• v.8 no.1
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• pp.129-133
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• 2006

To develope a high value-added fiber products which is useful in the human body physiology, the Macban stone was deposited on the PET fabric by sputtering and its effects were investigated. Then, a Macban stone target was prepared for sputtering treatment and treated on the PET fabric by RF sputtering process. After treatment, surface observation by SEM, far-infrared emissivity and emissive power, the fastness to washing and light, bacteriostatic rate, electrostatic, drape stiffness, and breaking strength of PET fabric were investigated. From these investigation, the following conclusions were obtained. 1) The Macban stone was able to deposit on the PET fabric, by the RF sputtering treatment which is eco-friendly dry textile finishing. 2) The far-infrared emissivity and emissive power of sputtered PET fabrics were increased. 3) When PET fabric was treated by sputtering with Macban stone, the amount of deposited Macban stone increased with increasing treatment time and it was deposited on the fabric surface firmly. 4) The bacteriostatic rate of sputtered PET fabrics was about 20%. 5) The electrostatic charge of fiber surface was reduced by sputtering. 6) The fastness washing to light of dyed fabric were improved by the deposition of Macban stone, but the breaking strength was not changed by sputtering. 7) The drape stiffness of sputtered PET fabrics increased with increasing treatment time.

• Journal of Soil and Groundwater Environment
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• v.7 no.2
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• pp.13-22
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• 2002

Soil washing by surfactants is a technology to enhance mobilization and subsequent degradation of oil pollutants by reducing the surface tension of pollutants which is combined with soil. In this study, biosurfactant, rhamnolipid was produced from Pseudomonas aemginosa ATCC 9027 which had an excellent biodegradable activity in soil without causing secondary pollution. Effects of chemical surfactants on the removal of diesel from diesel-contaminated soil were compared to those of biosurfactants including rhamnolipid. Diesel removal efficiency by rhamnolipid extracted from P. aeruginosa culture broth was over 95% in both batch and column washing test in 5,000ppm diesel-contaminated soil with 1% surfactants after washing for 24 hours. On the contrary, the results of chemical surfactants were below 50∼80%, The chemical surfactants with HLB value(8∼15) showed more then 75% efficiency of diesel removal. But, when the HLB values were below 8 or over 15. their efficiency were observed as less then 60% of diesel removal. Rhamnolipid, biologically produced surfactants, may also be promising agent for enhancing diesel removal from contaminated soil.